Engines, including compression-ignition engines, spark-ignition engines, gasoline engines, gaseous fuel-powered engines, and other internal combustion engines, may operate more effectively with fuel from which contaminates have been removed prior to the fuel reaching a combustion chamber of the engine. In particular, fuel contaminates, if not removed, may lead to undesirable operation of the engine and/or may increase the wear rate of engine components, such as, for example, fuel system components.
Effective removal of contaminates from the fuel system of a compression-ignition engine may be particularly important. In some compression-ignition engines, air is compressed in a combustion chamber, thereby increasing the temperature and pressure of the air, such that when fuel is supplied to the combustion chamber, the fuel and air mixture ignite. If water and/or other contaminates are not removed from the fuel, the contaminates may interfere with and/or damage, for example, fuel injectors, which may have orifices manufactured to exacting tolerances and shapes for improving the efficiency of combustion and/or reducing undesirable exhaust emissions. Moreover, the presence of water in the fuel system may cause considerable engine damage and/or corrosion in the injection system.
Fuel filtration systems serve to remove contaminates from the fuel. For example, some conventional fuel systems may include a primary fuel filter, which removes water and large particulate matter, and a secondary fuel filter, which removes a significant portion of remaining particulate matter (e.g., smaller contaminates), such as fine particulate matter. A typical secondary fuel filter may include a filter element contained within in a housing. The filter element may be arranged within the housing, such that a given volume of fuel is filtered by the filter element. Thus, in a system including a primary filter and a secondary filter, a given volume of fuel is filtered via filtration media twice—once in the primary filter where water and relatively large particulate matter may be removed, and once in the secondary filter where relatively small particulate matter may be removed. In some systems, attempts to improve the effectiveness of filtration systems have resulted in providing additional, separate fuel filters to supplement the primary and secondary fuel filters. The addition of such supplemental fuel filters, however, may be undesirable due, for example, to space and/or packaging constraints associated with the environment of the engine, which may render adding supplemental fuel filters problematic.
An attempt to provide desired filtration is described in U.S. Patent Application Publication No. US 2010/0051524 A1 (“the '524 publication”) to Marshall et al., published Mar. 4, 2010. Specifically, the '524 publication discloses a return flow filtration assembly for filtering return hydraulic fluid. The filtration assembly includes a first return fluid chamber including a first inlet and first and second outlets. The second outlet is configured to be coupled to a secondary return flow filter for providing micro-filtering of the return fluid. The first outlet includes a restriction element for restricting flow through the first outlet and generating an artificial back pressure within the first return fluid chamber to drive fluid through the second outlet when the second outlet is coupled to a secondary return flow filter.
Although the return flow filtration assembly of the '524 publication may provide for supplemental filtration, it may suffer from a number of possible drawbacks. For example, it may use space inefficiently for some applications, require a relatively complex flow arrangement, and may still not provide a desirable level of filtration.
The filter element and filter assembly disclosed herein may be directed to mitigating or overcoming one or more of the possible drawbacks set forth above.